Bill - G4WJS,
  OK on the suggestion of switching to Meinberg NTP instead of D4.EXE,
which I have been using successfully for years. Today, the problem of poor
odd cycle and almost no even cycle FT8 decodes started again. I checked and
found the Windows Internet Time Sync tool was disabled. One would think
that if D4.EXE was the cause of the problem, disabling it would stop the
anomaly, so I shut down D4.EXE, but the poor decode problem continued.

Note that after a week of not leaving Chrome running, I started it again
yesterday and left it running. When the poor decode problem started again
today, I checked Task Manager and found that Chrome's memory use had
increased to over 1.3 GB. That is still a small fraction of the 16GB of
available RAM.

What might cause this poor and asymmetrical number of decoded FT8 stations
with the number of odd cycle decodes being greater than the almost zero
number of even cycle decodes?

Is it possible that some of the JT9.exe decoder code in RAM is getting
contaminated?

I'm in the process of bringing a 4 core computer online, replacing the dual
core computer now in use for WSJT-X. It will use Meinberg NTP. Hopefully
the poor decode problem will go away.with the new box.

73,
Rich - K1HTV
= = -

From: Bill Somerville <[email protected]>
To: [email protected]
Cc:
Bcc:
Date: Mon, 19 Apr 2021 18:07:49 +0100
Subject: Re: [wsjt-devel] Few FT8 decodes on Even cycles
Hi Rich,

you describe symptoms that could be explained by your time synchronization
application making step changes, that is sure to cause discontinuities in
the audio streams which in turn are very likely to disrupt decoding of all
signals in periods where that happens. One cause of this could be multiple
time sync applications running simultaneously, e.g. not disabling the
Windows Internet Time Sync tool if you are running another 3rd party time
sync tool. Note also that we no longer recommend SNTP time sync tools as
they are prone to this sort of time stepping on systems that keep poor time
when unsynchronized. On MS Windows the Meinberg NTP Client is a proper NTP
implementation and only steps the time during initialization, if configured
to do so, to get a fast synchronization. There are other time sync tools
that implement NTP rather than SNTP, if Meinberg is not to your liking. On
other platforms the default network time sync tool will be a full NTP
implementation like the *nix ntpd or more modern chronyd, so there just
enabling the system network time synchronization is sufficient.

73
Bill
G4WJS.
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